The invention relates to the technical field of floor and wall coverings that use polyvinyl chloride or similar materials.
The Applicant is a European leader in the manufacture of this type of floor and wall covering and is aware that laying such coverings in reentrant corners is performed by running them up like a skirting board.
A first method which is currently widely used involves the following phases. This process is illustrated in FIGS. 1 and 2. A quadrant-shaped piece (1) which is fixed by bonding or otherwise its longitudinal end parts to the opposite facing parts of the floor and walls is placed along the joining line between the floor and the walls. Then, the floor covering is offered up into the corner area by allowing it to run up into contact with the corresponding vertical surfaces of the wall. This involves previously cutting the floor covering along a line (2) at 45°, the end part of which corresponds to the bottom part of the joint with the 45° line extending up as far as the upper longitudinal end of the floor covering. Forming the corner in the two successive vertical planes creates a fold due to the excess material and, in order to avoid excess thickness, the excess pieces of material must be cut away on a trial-and-error basis. This operation is performed in situ and is far from practical. The floor covering must then be bonded into the reentrant corner and the opposite edges either side of the 45° line must be welded. This removal of excess material is necessary in order to prevent excess thicknesses in the area in question. The difficulty involved is real and demands considerable expertise on the part of the operative because cutting the floor covering in order to eliminate excess thickness is far from easy to achieve. This hot welding by depositing a weld bead (3) starts from the extreme reentrant point along the oblique line. One of the difficulties encountered is to master the quality of welding which can only be checked visually. In practice, it has been found that if there is even the slightest initial cracking, sealing will not be achieved.
Another problem is the fact that the welding operation in corners using a roller or nozzle may cause damage to the floor covering in the corner such as, for instance, burns on the floor covering and geometrical deformation, bulges etc. and an untidy visual appearance.
This solution is widely used given the lack of satisfactory alternate solutions and has yet another drawback. The corner parts can be considered as dust traps and facilitate the accumulation of dust and dirt of all kinds and are therefore areas that are particularly prone to soiling. However, floor and wall coverings of the type described are widely used on public and private premises where hygiene is an absolute must. This applies in the case of hospitals for example. The manual or mechanised means of cleaning and cleaning tools used of the brush and broom type do not make it possible to ensure thorough cleaning because it is not possible to access the extreme part of the corner.
It is therefore apparent that this solution is relatively impractical and has many disadvantages.
The Applicant's approach, around fifteen years ago, was to suggest a different solution based on separately fitted thermoformed corner components shown in FIG. 3. This solution which initially seemed attractive turned out to be relatively impractical in use and was abandoned in favour of the old method. This second solution involved producing corner components (4) made of plastic with predefined finished shapes that fit perfectly into the corner area and bonding them to the opposite facing parts of the floor and the walls. In fact, management and the necessary logistics to manufacture and install them remained onerous. The plumbness and squareness of the successive walls relative to the floor is far from perfect in practice and then becomes a problem during preliminary fitting and arrangement of these thermoformed corner components relative to the walls. In addition, another major drawback was the fact that there was loss of uniformity between the characteristics and decorative features of floor coverings and the corner components.
This second technology which was used by the Applicant was abandoned because it was impossible to utilise it on an industrial scale.
The Applicant therefore went back to the initial solution even though it had and still has many disadvantages.
Faced with this situation, the Applicant nevertheless continued its research in order to find other alternative solutions.